Fair enough. It appears that lumping the two sets of data from the
differing corpora yields misleading results. So here is the raw
data, recalculated, separating the MUMS Books database (first column)
and the JACKPHY database (second column), sorted in descending
frequency by number of occurrences in the MUMS Books database.

Comparing the two sets of data, it is clear that the JACKPHY database
contains an anomalously high frequency of macrons, breves, and dot belows,
and an anomalously low frequency of acutes, graves, carons, and tildes,
etc.

For the base letters, the JACKPHY database has an anomalously high
proportion of o's, u's, h's, k's, and v's carrying diacritics, and
an anomalously low proportion of e's, n's, and c's, etc.